(a) Field of the Invention
The present invention is related to an electric machinery with a permanent magnet magnetic pole wrapped by a magnetic pole or a magnetic circuit of an individual magnetic pole, and more particularly, to a permanent magnet (PM) magnetic pole wrapped between the individual magnetic pole and the magnetic circuit that is disposed in various types of electric machinery of the prior art.
(b) Description of the Prior Art
Whereas a conventional AC or DC revolution or linear electric machinery either of commutator, brush, brushless, ring-brush, synchronous, asynchronous, internal revolving, external revolving, revolving with an electric magnetic structure at middle, double-acting, triple-acting, multi-layer, multi-ring, linear, DC brushless, or inverter electric machinery, or an electric machinery functioning as a generator or as a motor or as both a generator and a motor, coupling transmission device, as an EME vortex coupling transmission device, or an EME vortex braking device, is usually provided with a magnetic pole structure to produce EM effect operation.
A magnetic pole structure of the prior art is comprised of:                a conducted winding exciting magnetic pole having on its polar face disposed with a PM magnetic pole indicate cumulative or differential; or        a magnetic pole structure of DC or AC electrically conducted winding excitation; or        a PM magnetic pole structure.        
As illustrated in FIG. 1 of the accompanying drawings for a schematic view showing a structure of a conventional PM magnetic pole, the structure features an advantage of not requiring a magnetic field exciting current but is found with a flaw of having its magnetic power to be weakened by inverse excitation in the course of the operation of an electric machinery.